CROSS-REFERENCE TO RELATED APPLICATIONSThis is a continuation of International Application PCT/JP2019/049125 which is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELDThe present invention relates to a high-frequency treatment tool, a medical system, and a method for removing attached matter on a high-frequency treatment tool.
BACKGROUND ARTIn the related art, there is a known high-frequency treatment tool that transendoscopically makes an incision in biological tissue such as a mucous membrane (for example, see Patent Literature 1). The high-frequency treatment tool described inPatent Literature 1 includes a rod-like electrode that protrudes from a distal end of a sheath in the longitudinal direction. The high-frequency treatment tool described inPatent Literature 1 makes a cautery incision in biological tissue by bringing the electrode into contact with the biological tissue in a state in which the electrode is energized with a high-frequency current.
With the high-frequency treatment tool described inPatent Literature 1, when a cautery incision is made in biological tissue, the incising performance thereof deteriorates as a result of a burnt deposit of the incised biological tissue becoming attached to the electrode. Accordingly, in the case in which a burnt deposit of biological tissue becomes attached to the electrode, treatment is performed by temporarily removing the high-frequency treatment tool from an endoscope channel and by inserting the high-frequency treatment tool into the endoscope channel again after removing the burnt deposit of the biological tissue from the electrode.
CITATION LISTPatent Literature- {PTL 1} PCT International Publication No. WO 2014/042039
SUMMARY OF INVENTIONOne aspect of the present invention is a high-frequency treatment tool including: a sheath having an inner hole that passes therethrough in a longitudinal direction; a first electrode portion that is formed in a rod shape, that passes through the inner hole of the sheath to protrude from a distal end of the sheath, and that is configured to apply a high-frequency current; a second electrode portion that is disposed at a position at which the second electrode portion is electrically connected with the first electrode portion; and a power source that uses the first electrode portion as a negative electrode, that uses the second electrode portion as a positive electrode, and that supply a current between the first electrode portion and the second electrode portion so that a state in which attached matter attached to the first electrode portion is lifted from the first electrode portion due to osmosis is created.
Another aspect of the present invention is a method for removing attached matter on a high-frequency treatment tool, the method including: making a first electrode portion disposed in a sheath protrude from a distal end of the sheath toward a distal end, the first electrode portion being formed in a rod shape; releasing an electrolyte liquid from the distal end of the sheath toward the first electrode portion; supplying a current between the first electrode portion and a second electrode portion so that a state in which attached matter attached to the first electrode portion is lifted from the first electrode portion due to osmosis is created, the second electrode portion being disposed at a position at which the second electrode portion is electrically connected with the first electrode portion; and pulling the first electrode portion into the sheath.
BRIEF DESCRIPTION OF DRAWINGSFIG. 1 is an overall configuration diagram of a medical system according to a first embodiment of the present invention.
FIG. 2 is an overall configuration diagram of a high-frequency treatment tool inFIG. 1 when excising tissue.
FIG. 3 is an overall configuration diagram of the high-frequency treatment tool inFIG. 2 when removing a burnt deposit of the biological tissue.
FIG. 4 is a flowchart for explaining a high-frequency treatment tool operating method employing the high-frequency treatment tool inFIG. 2.
FIG. 5 is an overall configuration diagram of a medical system according to a modification of the first embodiment of the present invention.
FIG. 6 is a diagram for explaining a manner in which a high-frequency current is biased toward a negative side.
FIG. 7 is an overall configuration diagram of a high-frequency treatment tool according to a second embodiment of the present invention when excising tissue.
FIG. 8 is an overall configuration diagram of the high-frequency treatment tool inFIG. 7 when removing a burnt deposit of the biological tissue.
FIG. 9 is a longitudinal cross-sectional view showing the vicinity of a sheath distal-end portion of a high-frequency treatment tool according to a first modification of the second embodiment of the present invention.
FIG. 10 is a side view showing the vicinity of a sheath distal-end portion, which is a further modification of the high-frequency treatment tool according to the first modification of the second embodiment of the present invention.
FIG. 11 is a longitudinal cross-sectional view of the vicinity of the sheath distal-end portion inFIG. 10.
FIG. 12 is a cross-sectional view taken across A-A inFIG. 10.
FIG. 13 is a cross-sectional view taken across B-B inFIG. 10.
FIG. 14 is a perspective view showing a cutter inFIG. 13.
FIG. 15 is a longitudinal cross-sectional view showing a state in which an electrode portion of the high-frequency treatment tool inFIG. 10 is pulled into a sheath.
FIG. 16 is a side view showing the vicinity of the sheath distal-end portion of the high-frequency treatment tool according to the second modification of the second embodiment of the present invention.
FIG. 17 is a longitudinal cross-sectional view of the vicinity of the sheath distal-end portion inFIG. 16.
FIG. 18 is a cross-sectional view taken across D-D inFIG. 16.
FIG. 19 is an enlarged view of the sheath distal-end portion inFIG. 17.
FIG. 20 is a cross-sectional view taken across C-C inFIG. 16.
FIG. 21 is a longitudinal cross-sectional view showing a state in which an electrode portion of the high-frequency treatment tool inFIG. 16 is pulled into a sheath.
DESCRIPTION OF EMBODIMENTSFirst EmbodimentA high-frequency treatment tool, a medical system, and a high-frequency treatment tool operating method according to a first embodiment of the present invention will be described below with reference to the drawings.
As shown inFIG. 1, amedical system100 according to this embodiment includes: aflexible endoscope31; a high-frequency treatment tool1 that makes an incision in biological tissue of a patient (subject) X; aprocessor33 that performs tasks such as overall control of themedical system100 and endoscope image generation; and so forth. InFIG. 1,reference sign35 indicates a monitor that displays an endoscope image or the like generated by theprocessor33. In addition,reference sign37 indicates a universal cable that connects theendoscope31 and the high-frequency treatment tool1 to theprocessor33.
Theendoscope31 includes a long,thin insertion portion41 that can be inserted into a body of a patient X (into a living body and anendoscope operating portion43 for operating theinsertion portion41, feeding of air and liquids, endoscope image acquisition, and so forth.
Theinsertion portion41 is provided with achannel41ainto which the high-frequency treatment tool1 can be inserted.
The high-frequency treatment tool1 passes through thechannel41aof theendoscope31, and a distal end thereof is introduced into the body of the patient X. As shown inFIGS. 1-3, the high-frequency treatment tool1 includes: a long, thincylindrical sheath3 possessing flexibility; aknife portion5 that is moved forward and rearward at a distal end of thesheath3; aknife operating portion6 for performing operations such as changing the protrusion amount of theknife portion5; an opposing electrode (second electrode portion)7 that is disposed outside the body of the patient X; apower supply device9 that supplies currents to theknife portion5 and theopposing electrode7; and a liquid feeding means11 that supplies a physiological saline solution (liquid) W between theknife portion5 and theopposing electrode7. In the following, a distal-end side of thesheath3 is assumed to be forward, and a basal-end side of thesheath3 is assumed to be rearward.
Thesheath3 is formed so as to allow the insertion thereof into thechannel41aof theendoscope31. Thesheath3 includes, for example, a cylindrical coil (not shown) that has aninner hole3athat passes therethrough in a longitudinal direction and a cylindrical insulation tube (not shown) that covers an outer circumference of the coil. Theinner hole3aalso serves as a flow channel of the liquid. The liquid feeding means11 is a syringe, a pump, or the like that is connected to theinner hole3a, and the physiological saline solution W is released from the distal end of thesheath3 via theinner hole3a.
Theknife portion5 includes: an electrode portion (first electrode portion)13 that can be made to protrude from the distal end of thesheath3 by passing through theinner hole3aof thesheath3; and a substantially hemispherical distal-end tip15 that is secured to a distal end of theelectrode portion13.
Theelectrode portion13 includes: aneedle13awhich is a rod-like electrode having a constant diameter over the entire length thereof; and anelectrode13bprovided at a distal end of theneedle13a.
Theneedle13ais provided so as to be relatively movable in theinner hole3aof thesheath3 in the longitudinal direction of thesheath3. The movement of theneedle13ais controlled by theknife operating portion6. Theneedle13ais formed of, for example, a conductive material such as SUS (stainless steel).
Theelectrode13bis formed of, for example, a conductive material such as SUS, as with theneedle13a, and is integrally formed at the distal end of theneedle13a. Theelectrode13bextends, for example, from the distal end of theneedle13ain a radiating manner in a direction orthogonal to the longitudinal-axis direction of theneedle13a.
The distal-end tip15 is formed of, for example, a heat-resistant electrical insulator such as a ceramic. The distal-end tip15 is disposed, for example, with aspherical surface portion15athereof facing away from thesheath3 and aflat surface portion15bfacing toward thesheath3. Theelectrode13bis secured to theflat surface portion15b, and theelectrode13bextends in a radiating manner along theflat surface portion15b.
Theknife operating portion6 is disposed on the basal-end side of thesheath3. Theknife operating portion6 includes, for example, an operating portion body that has a longitudinal axis, an operating slider that is provided in the operating portion body so as to be movable in the longitudinal-axis direction of the operating portion body, and an operating wire that connects the operating slider and the knife portion5 (all of which are not shown).
The operating wire is disposed inside theinner hole3aof thesheath3, a distal end thereof is connected to the basal-end portion of theneedle13aand a basal end thereof is connected to the operating slider. When the operating slider is moved in the longitudinal-axis direction of the operating portion body, a pressing force and a pulling force are transmitted to theneedle13aas a result of the operating wire being pushed and pulled in the longitudinal direction of thesheath3. Accordingly, theneedle13ais moved with respect to thesheath3 in the longitudinal direction of thesheath3. In other words, theknife portion5 is moved forward and rearward with respect to thesheath3 in association with the forward and rearward motions of the operating wire.
The opposingelectrode7 is formed of a conductive material such as SUS, as with theneedle13aand theelectrode13b. The opposingelectrode7 is attached to, for example, the back of the patient X. Note that the material of theneedle13a, theelectrode13b, and the opposingelectrode7 is not limited to SUS, and all of these components may be made of any conductive material.
Thepower supply device9 includes: a high-frequency power source17 that supplies high-frequency currents between theelectrode portion13 and the opposingelectrode7; a constant-currentDC power source19 that supplies direct currents between theelectrode portion13 and the opposingelectrode7; and aswitching mechanism21 that switches between the high-frequency current supply between theelectrode portion13 and the opposingelectrode7 and the direct current supply therebetween. Afoot switch39 for an operator to control the high-frequency power source17, the constant-currentDC power source19, and theswitching mechanism21 is connected to the power supply device9 (seeFIG. 1).
Theswitching mechanism21 includes: afirst switch21athat connects theneedle13ato one of a knife-side terminal17aof the high-frequency power source17 and a negative electrode terminal (−)19bof the constant-currentDC power source19 in a switchable manner; and asecond switch21bthat connects the opposingelectrode7 to one of an opposing-electrode-side terminal17bof the high-frequency power source17 and a positive electrode terminal (+)19aof the constant-currentDC power source19 in a switchable manner.
Next, the operation of the high-frequency treatment tool1 and themedical system100 according to this embodiment will be described below.
In order to transendoscopically excise a mucous membrane in a body by using themedical system100 according to this embodiment, first, an injection needle (not shown) is introduced into the body of a patient X via thechannel41aof theendoscope31. Then, a lesion site is lifted up by injecting a physiological saline solution into a submucosa of a site that is assumed to be a lesion to be excised, while viewing an endoscope image displayed on themonitor35.
Next, a high-frequency treatment tool (not shown) having a conventional needle-like electrode is introduced into the body via thechannel41aof theendoscope31, and an initial incision is made, the initial incision making a hole in a portion of the mucous membrane in the periphery of the lesion site. After making the initial incision, the high-frequency treatment tool is removed from thechannel41a.
Subsequently, an operator switches the tool in hand with the high-frequency treatment tool1 and introduces thesheath3 into the body from the distal-end side thereof via thechannel41aof theendoscope31, as shown inFIG. 1, in a state in which theknife portion5 is maximally moved rearward. Because the distal-end tip15, which is disposed at the distal end of thesheath3, comes into the viewing field of theendoscope31 when the distal end of thesheath3 is made to protrude from the distal end of thechannel41aof theendoscope31, the operator performs treatment while checking an endoscope image acquired by means of theendoscope31 on themonitor35.
In the state in which theknife portion5 is maximally moved rearward, only the distal-end tip15 is exposed from the distal end of thesheath3; therefore, theknife portion5 is not deeply inserted into biological tissue S. In addition, because thespherical surface portion15aof the substantially hemispherical distal-end tip15 is disposed facing forward, the biological tissue S that comes into contact with the distal-end tip15 is not damaged.
Next, theknife portion5 is maximally moved forward by means of theknife operating portion6. Doing so puts theneedle13aand theelectrode13bin a state of being exposed forward with respect to thesheath3. In this state, theknife portion5 is inserted, from the distal-end tip15, into the hole formed in advance by the initial incision.
Next, as shown inFIG. 2, theneedle13aand the knife-side terminal17aof the high-frequency power source17 are connected by means of thefirst switch21a, and the opposingelectrode7 and the opposing-electrode-side terminal17bof the high-frequency power source17 are connected by means of thesecond switch21b.
In this state, theknife portion5 is moved in a direction in which an incision is made, intersecting the longitudinal axis, while supplying the high-frequency currents between theneedle13aand the opposingelectrode7 as well as between theelectrode13band the opposingelectrode7 from the high-frequency power source17. For example, by hooking a section from the distal-end portion of theneedle13ato theelectrode13bon the mucous membrane in the periphery of the lesion site, it is possible to efficiently make a cautery incision in the periphery of the lesion site.
Because the distal-end tip15 provided at the distal end of theknife portion5 is formed of a material having an insulating property, an incision is not made in the biological tissue S that is in contact with the distal-end tip15, even if the high-frequency currents are supplied to theneedle13aand theelectrode13b. Therefore, it is possible to prevent the problem of the distal-end tip15 making an incision in submucosal tissue.
In this case, while the cautery incision is being made in the biological tissue S, burnt deposits (attached matter) of the incised biological tissue S become attached to theneedle13aand theelectrode13b. When the burnt deposits of the biological tissue S become attached to theneedle13aand theelectrode13b, the incising performance of theelectrode portion13 deteriorates; therefore, it is necessary to remove the burnt deposits of the biological tissue S from theneedle13aand theelectrode13b.
A method for operating the high-frequency treatment tool1 for removing the burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13bwill be described below with reference to the flowchart inFIG. 4.
In the case in which burnt deposits of the biological tissue S become attached to theneedle13aand theelectrode13b, first, the liquid feeding means11 is activated in the state in which the distal end of thesheath3 remains inserted inside the body via thechannel41aof theendoscope31. Consequently, the physiological saline solution W is released to the periphery of theelectrode portion13 from the distal end of thesheath3, as shown inFIG. 3 (step S1). Accordingly, theneedle13aand the biological tissue S as well as theelectrode13band the biological tissue S are electrically connected as a result of the physiological saline solution W being interposed therebetween.
Next, as shown inFIG. 3, theneedle13aand thenegative electrode terminal19bof the constant-currentDC power source19 are connected by means of thefirst switch21a, and the opposingelectrode7 and thepositive electrode terminal19aof the constant-currentDC power source19 are connected by means of thesecond switch21b. In this state, the direct currents are supplied between theneedle13aand the opposingelectrode7 as well as between theelectrode13band the opposingelectrode7 from the constant-current DC power source19 (step S2).
Consequently, the physiological saline solution W moves to the periphery of theelectrode portion13 due to osmosis. Specifically, the physiological saline solution W permeates the burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13band collects in the periphery of theneedle13aand theelectrode13b. Accordingly, a state in which the burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13bare lifted from theneedle13aand theelectrode13bis created, and thus, it becomes easier for the burnt deposits of the biological tissue S to peel off from theneedle13aand theelectrode13b.
In the case in which the burnt deposits of the biological tissue S are removed from theneedle13aand theelectrode13b(“YES” in step S3), the removal processing of the burnt deposits of the biological tissue S is ended, and the treatment is restarted.
On the other hand, in the case in which the burnt deposits of the biological tissue S are not removed from the electrode portion13 (“NO” in step S3), steps S1 and S2 are repeated until the burnt deposits of the biological tissue S are removed from theelectrode portion13.
As has been described above, with the high-frequency treatment tool1 and the method for operating the high-frequency treatment tool1 according to this embodiment, in the case in which the burnt deposits of the biological tissue S become attached to theneedle13aand theelectrode13b, it is possible to remove the burnt deposits of the biological tissue S from theneedle13aand theelectrode13bin a state in which thesheath3 remains inserted in thechannel41aof theendoscope31 simply by supplying the direct currents between theneedle13aand the opposingelectrode7 as well as between theelectrode13b. and the opposingelectrode7.
Therefore, even if burnt deposits of the biological tissue S become attached to theneedle13aand theelectrode13b, it is possible to enhance the work efficiency by reducing the time and effort required to remove the high-frequency treatment tool1 from thechannel41aof theendoscope31. In addition, it is possible to share the opposingelectrode7 between when making an incision in the biological tissue S and when removing the burnt deposits of the biological tissue S attached to theelectrode portion13, and thus, it is possible to reduce the number of components.
In this embodiment, the high-frequency currents and the direct currents are switched; however, alternatively, for example, the high-frequency currents and the direct currents may be applied to theelectrode portion13 in an overlapping manner. In the case in which the high-frequency currents and the direct currents are overlapped, the two types of currents may be constantly overlapped or may be overlapped after applying the high-frequency currents.
Regarding the direct currents, it suffices, so long as the capacitance thereof is high enough, to apply the negative bias required to cause the burnt deposits of the biological tissue S attached to theelectrode portion13 to peel off therefrom.
It is possible to modify this embodiment as in the following configuration.
A high-frequency treatment tool1 according to the modification of this embodiment consists of, for example, thesheath3, theknife portion5, the opposingelectrode7, the liquid feeding means11, and the high-frequency power source17, as shown inFIG. 5. Thesheath3, theknife portion5, the opposingelectrode7, and the liquid feeding means11 are configured in the same manner as in the first embodiment. The positive side of the high-frequency power source17 is directly connected to theneedle13awithout passing through theswitching mechanism21, and the negative side thereof is directly connected to the opposingelectrode7 without passing through theswitching mechanism21.
As shown inFIG. 6, the direct currents are made to overlap with the high-frequency currents. For example, the high-frequency currents are biased toward the negative side. Accordingly, because the time during which a negative volage is applied to theneedle13aincreases, theneedle13aeffectively behaves in the same manner as when being negatively charged. Therefore, an equivalent effect as when the direct currents are applied is achieved.
With this modification, because the equivalent effect as when the direct currents are applied is achieved by means of the configuration of the high-frequency treatment tool itself, an additional constituent component is not required, and thus, it is possible to reduce costs.
Second EmbodimentNext, a high-frequency treatment tool, a medical system, and a high-frequency treatment tool operating method according to a second embodiment of the present invention will be described.
A high-frequency treatment tool1 according to this embodiment includes, for example, as shown inFIGS. 7 and 8, a DC electrode (second electrode portion)23 as a separate component from the opposingelectrode7, and differs from the first embodiment in that theDC electrode23 is disposed in the distal-end portion of thesheath3.
In the following, the portions having the same configurations as the high-frequency treatment tool1 according to the first embodiment will be given the same reference signs, and the descriptions thereof will be omitted. The other configurations of themedical system100 are the same as those in the first embodiment.
TheDC electrode23 is disposed at a position where theDC electrode23 covers the outer circumference of thesheath3 in the distal-end portion of thesheath3.Wiring25 for supplying power to theDC electrode23 is disposed inside thesheath3. TheDC electrode23 and thewiring25 are electrically connected with each other. TheDC electrode23 is formed of, for example, a conductive material such as SUS.
In this embodiment, theswitching mechanism21 is provided with athird switch21cthat switches between connection and disconnection between thewiring25 of theDC electrode23 and thepositive electrode terminal19aof the constant-currentDC power source19. Thesecond switch21bswitches between connection and disconnection between the opposingelectrode7 and the opposing-electrode-side terminal17bof the high-frequency power source17.
Next, the operation of the high-frequency treatment tool1 according to this embodiment will be described below.
In the case in which a mucous membrane in a body is transendoscopically excised by using the high-frequency treatment tool1 according to this embodiment, as shown inFIG. 7, theneedle13aand the knife-side terminal17aof the high-frequency power source17 are connected by means of thefirst switch21a, and the opposingelectrode7 and the opposing-electrode-side terminal17bof the high-frequency power source17 are connected by means of thesecond switch21b. On the other hand, thewiring25 of theDC electrode23 and thepositive electrode terminal19aof the constant-currentDC power source19 are put into a disconnected state by means of thethird switch21c, thereby putting theDC electrode23 into an electrically floating state.
In this state, as a result of moving theknife portion5 in the incising direction, intersecting the longitudinal axis, while supplying high-frequency currents between theneedle13aand the opposingelectrode7 as well as between theelectrode13band the opposingelectrode7 from the high-frequency power source17, a cautery incision is made in the periphery of a lesion site.
Next, in the case in which burnt deposits of the biological tissue S become attached to theneedle13aand theelectrode13b, the physiological saline solution W is released to the periphery of theelectrode portion13 from the distal end of thesheath3 by means of the liquid feeding means11, as shown inFIG. 8, in the state in which the distal end of thesheath3 remains inserted inside the body via thechannel41aof theendoscope31. Accordingly, theneedle13aand theDC electrode23 as well as theelectrode13band theDC electrode23 are electrically connected as a result of the physiological saline solution W being interposed therebetween.
Next, theneedle13aand thenegative electrode terminal19bof the constant-currentDC power source19 are connected by means of thefirst switch21a, and thewiring25 of theDC electrode23 and thepositive electrode terminal19aof the constant-currentDC power source19 are connected by means of thethird switch21c. On the other hand, the opposingelectrode7 and the opposing-electrode-side terminal17bof the high-frequency power source17 are put into a disconnected state by means of thesecond switch21b, thereby putting the opposingelectrode7 into an electrically floating state.
In this state, direct currents are supplied between theneedle13aand theDC electrode23 as well as between theelectrode13band theDC electrode23 from the constant-currentDC power source19. Consequently, the physiological saline solution W in the periphery of theelectrode portion13 permeates burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13band collects in the periphery of theneedle13aand theelectrode13bdue to osmosis. Accordingly, it becomes easier for the burnt deposits of the biological tissue S to peel off from theelectrode portion13.
In the case in which burnt deposits of the biological tissue S are removed in this embodiment, as a result of applying the direct currents to theDC electrode23 disposed in the distal-end portion of thesheath3, instead of the opposingelectrode7, the direct currents are concentrated in the periphery of theelectrode portion13; therefore, it is possible to reduce the amount of current flowing inside the body.
It is possible to modify this embodiment as in the following configurations.
In this embodiment, theDC electrode23 is disposed at the position where theDC electrode23 covers the distal-end portion of thesheath3. As a first modification, for example, theDC electrode23 may be accommodated in the distal-end portion of thesheath3, as shown inFIG. 9. TheDC electrode23 is formed in a tubular shape and is secured to an inner surface of theinner hole3aof thesheath3.
With this modification, as a result of theDC electrode23 being accommodated in the distal-end portion of thesheath3, when excising a mucous membrane in a body, in other words, when applying a high-frequency current to theknife portion5, it is unlikely that theDC electrode23 comes into contact with the biological tissue S. Therefore, an unnecessary discharge resulting from theDC electrode23 coming into contact with the biological tissue S is prevented, and thus, it is possible to prevent a deterioration in the incising performance.
As a second modification, for example, the high-frequency treatment tool1 may includecutters27 disposed at the distal-end portion of theDC electrode23, as shown inFIGS. 10 and 11. Each of thecutters27 is disposed so that acutting edge27athereof points toward theelectrode portion13.
In the example shown inFIG. 11, thesheath3 consists of acylindrical coil3chaving theinner hole3a, acylindrical tube3dthat covers an outer circumference of thecoil3c, and a cylindrical sheath distal-end member3ethat is disposed forward with respect to thecoil3cand thetube3d.
Thecoil3cis formed of, for example, a conductive material such as SUS. Thetube3dis formed of, for example, an insulator such as PTFE (polytetrafluoroethylene). The sheath distal-end member3eis formed of, for example, an insulator such as a ceramic.
A DCpower supply cable29 that is electrically connected to theDC electrode23 is disposed between thetube3dand thecoil3c. The DCpower supply cable29 is covered with an insulation coating.
In this modification, theneedle13ais provided so as to be relatively movable in the longitudinal direction of thesheath3. Theelectrode13bextends, for example, in a Y-shape along theflat surface portion15bof the distal-end tip15 with equal spacings in the circumferential direction about the longitudinal axis of theneedle13a, as shown inFIG. 12, and is secured to theflat surface portion15b.
Each of thecutters27 is, for example, a triangular prism-shaped member and an angular portion thereof formed by two adjacent side surfaces forms thecutting edge27a, as shown inFIGS. 13 and 14. Thecutter27 has thecutting edge27aextending in a radial direction of thesheath3 and is secured to a distal-end surface of thesheath3 in an orientation in which thecutting edge27afaces forward with respect to thesheath3. In the example shown inFIG. 13, threecutters27 are disposed at positions shifted in the circumferential direction about the longitudinal axis of theneedle13awith respect to theelectrode13bextending in the Y-shape.
The operation of the high-frequency treatment tool1 according to this modification will be described below.
In the case in which burnt deposits of the biological tissue S become attached to theelectrode portion13, the physiological saline solution W is released to the periphery of theelectrode portion13 from the distal end of thesheath3 in the state in which the distal end of thesheath3 remains inserted inside the body via thechannel41aof theendoscope31, and theneedle13aand theDC electrode23 as well as theelectrode13band theDC electrode23 are electrically connected.
Next, theneedle13ais used as a negative electrode, theDC electrode23 is used as a positive electrode, and direct currents are supplied between theneedle13aand theDC electrode23 as well as between theelectrode13band theDC electrode23 from the constant-currentDC power source19. Consequently, the physiological saline solution W in the periphery of theelectrode portion13 permeates burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13band collects in the periphery of theneedle13aand theelectrode13bdue to osmosis, as a result of which it becomes easier for the burnt deposits of the biological tissue S to peel off from theelectrode portion13.
Here, although the direct current application creates a state in which the burnt deposits of the biological tissue S are lifted from theneedle13aand theelectrode13b, there are cases in which the burnt deposits of the biological tissue S do not peel off and remain in a tubular shape around theneedle13aand theelectrode13b.
In this case, with this modification, theknife portion5 is moved by means of theknife operating portion6 in the direction in which theneedle13ais pulled into thesheath3, as shown inFIG. 15. Accordingly, the burnt deposits of the biological tissue S remaining in a tubular shape around theneedle13aand theelectrode13bare pressed against the cutting edges27aof thecutters27 at the distal end of thesheath3.
Then, as theneedle13ais pulled into thesheath3, cuts are made in the burnt deposits of the biological tissue S in the longitudinal-axis direction of theneedle13a. Consequently, theneedle13aand theelectrode13bcome off starting from the cuts in the burnt deposits of the biological tissue S and the burnt deposits of the biological tissue S peel off from theelectrode portion13.
Therefore, with the high-frequency treatment tool1 according to this modification, it is possible to more efficiently remove the burnt deposits of the biological tissue S from theelectrode portion13.
In this modification, theDC electrode23 is disposed at the position where theDC electrode23 covers the outer circumference of the distal-end portion of thesheath3. Alternatively, for example, theDC electrode23 may be accommodated in the distal-end portion of thesheath3, as shown inFIGS. 16 and 17.
In the example shown inFIGS. 16 and 17, thetube3dextends to the distal end of thesheath3, and the cylindrical sheath distal-end member3edisposed forward with respect to thecoil3cis covered with thetube3d. In addition, the sheath distal-end member3eis formed of a conductive material such as SUS and serves as theDC electrode23.
Each of thecutters27 has, for example, thecutting edge27aextending in the longitudinal direction of thesheath3 and is secured to the inner surface of the sheath distal-end member3ein an orientation in which thecutting edge27afaces radially inward with respect to thesheath3, as shown inFIGS. 18 and 19. In the example shown inFIGS. 18 and 19, threecutters27 are disposed at positions shifted in the circumferential direction about the longitudinal axis of theneedle13awith respect to theelectrode13bextending in the Y-shape shown inFIG. 20.
With this configuration also, as shown inFIG. 21, as a result of pulling theneedle13ainto thesheath3, burnt deposits of the biological tissue S remaining in a tubular shape around theneedle13aand theelectrode13bare pressed against the cutting edges27aof thecutters27 accommodated in the distal-end portion of thesheath3, and thus, cuts are made in the burnt deposits of the biological tissue S. Therefore, it is possible to efficiently remove the burnt deposits of the biological tissue S from theelectrode portion13.
Although this modification has been described in terms of the threecutters27 as an example, it suffices so long as cuts can be made in burnt deposits of the biological tissue S by means of thecutting edge27aof thecutter27, and the number ofcutters27 may be one, two, four, or more.
In this modification, theneedle13ais pulled into thesheath3 after supplying direct currents between theneedle13aand theDC electrode23 as well as between theelectrode13band theDC electrode23. Alternatively, direct currents may be supplied between theneedle13aand theDC electrode23 as well as between theelectrode13band theDC electrode23 after making cuts in burnt deposits of the biological tissue S attached to theneedle13aand theelectrode13bby means of the cutting edges27aof thecutters27 by pulling theneedle13ainto thesheath3 first. In this case also, it is possible to efficiently remove the burnt deposits of the biological tissue S from theelectrode portion13.
As has been described above, although the embodiments of the present invention have been described in detail with reference to the drawings, specific configurations are not limited to said embodiments, and design alterations or the like within a range that does not depart from the scope of the present invention are also encompassed. For example, the present invention is not limited to application to the above-described respective embodiments and modifications, the present invention may be applied to embodiments in which said embodiments and modifications are combined, as appropriate, without particular limitation.
In addition, although the liquid has been described in terms of the physiological saline solution W as an example, any liquid may be employed so long as the liquid is an electrolyte liquid, and, for example, a liquid or the like present in biological tissue S may be utilized as the liquid. In addition, although the subject has been described in terms of a human as an example, the present invention may be applied to, for example, non-human animals. In addition, the attached matter has been described in terms of burnt deposits of biological tissue S as an example, it suffices so long as the attached matter can be peeled off from theelectrode portion13 by means of osmosis, and it is not limited to burnt deposits of biological tissue S.
The following aspects can be also derived from the embodiments.
A first aspect of the present invention is a high-frequency treatment tool including: a first electrode portion that is capable of applying a high-frequency current employed in high-frequency treatment; a second electrode portion that is disposed at a position at which the second electrode portion is electrically connected with the first electrode portion; and a power supply portion that uses the first electrode portion as a negative electrode, that uses the second electrode portion as a positive electrode, and that is capable of supplying a direct current between the first electrode portion and the second electrode portion.
With this aspect, it is possible to make a cautery incision in biological tissue by bringing the first electrode portion into contact with the biological tissue in a state in which the first electrode portion is energized with the high-frequency current.
In the case in which attached matter, such as a burnt deposit of the biological tissue (hereinafter, a burnt deposit of the biological tissue will be described as an example), becomes attached to the first electrode portion as a result of making a cautery incision in the biological tissue, the direct current is supplied between the first electrode portion and the second electrode portion by means of the power supply portion by using the first electrode portion as a negative electrode and by using the second electrode portion as a positive electrode. Consequently, a liquid moves due to osmosis, and, as a result of the liquid permeating the burnt deposit of the biological tissue and collecting in the periphery of the first electrode portion, it becomes easier for the burnt deposit of the biological tissue attached to the first electrode portion to peel off therefrom.
Therefore, in the case in which a burnt deposit of biological tissue becomes attached to the first electrode portion while treatment is being performed in a living body via an endoscope channel, it is possible to remove the burnt deposit of the biological tissue from the first electrode portion in a state in which the first electrode portion or the like remains inserted in the endoscope channel. Accordingly, even if a burnt deposit of biological tissue becomes attached to the electrode portion, it is possible to enhance the work efficiency by reducing the time and effort required to remove the high-frequency treatment tool from the endoscope channel.
In the above-described aspect, the high-frequency treatment tool may include a sheath having an inner hole that passes therethrough in a longitudinal direction, wherein the first electrode portion may be formed in a rod shape and may pass through the inner hole of the sheath to protrude from a distal end of the sheath.
In the above-described aspect, the second electrode portion may be an opposing electrode that is disposed outside a body of a subject and the high-frequency current may be supplied between the opposing electrode and the first electrode portion when an incision is made in biological tissue.
With this configuration, it is possible to share the second electrode portion between when making an incision in the biological tissue and when removing a burnt deposit of the biological tissue attached to the first electrode portion, and thus, it is possible to reduce the number of components.
In the above-described aspect, the second electrode portion may be a DC electrode that is disposed in a distal-end portion of the sheath and that is switched to an electrically non-contact state with respect to the first electrode when an incision is made in biological tissue.
In the case in which a burnt deposit of the biological tissue is removed with this configuration, because the direct current is concentrated in the periphery of the first electrode portion, it is possible to reduce the amount of current flowing inside the body.
In the above-described aspect, the high-frequency treatment tool may include a cutter that is disposed in a distal-end portion of the second electrode portion with a cutting edge thereof pointing toward the first electrode portion, wherein the first electrode portion may be provided so as to be relatively movable in the longitudinal direction in the inner hole of the sheath.
In the case in which a burnt deposit of the biological tissue attached to the first electrode portion is removed with this configuration, as a result of relatively moving the first electrode portion and the sheath in a direction in which the first electrode portion is pulled into the sheath after supplying the direct current between the first electrode portion and the second electrode portion by means of the power supply portion, the burnt deposit of the biological tissue attached to the first electrode portion is pressed against the cutting edge of a cutter disposed in the distal-end portion of the sheath. Accordingly, a cut is made in the burnt deposit of the biological tissue by means of the cutting edge of the cutter; therefore, it is possible to more efficiently remove the burnt deposit of the biological tissue from the first electrode portion.
In the above-described aspect, the sheath may include a coil that has the inner hole and that is formed of a tubular conductive material, a tube that covers an outer circumference of the coil and that is formed of an insulator, and a sheath distal-end member that is disposed forward with respect to the coil and the tube and that is formed of a tubular insulator; the second electrode portion may be formed in a tubular shape that covers a periphery of the sheath distal-end member; and the cutter may be disposed at a distal end of the second electrode portion.
In the above-described aspect, the sheath may include a coil that has the inner hole and that is formed of a tubular conductive material and a tube that covers an outer circumference of the coil and that is formed of an insulator; the second electrode portion may be formed in a tubular shape that is covered with the tube; and the cutter may be disposed on an inner surface of the second electrode portion.
In the above-described aspect, the power supply portion may supply, in a state in which an electrolyte liquid is interposed between the first electrode portion and the second electrode portion, the direct current between the first electrode portion and the second electrode portion via the liquid.
In the above-described aspect, the high-frequency treatment tool may include a liquid feeding means for supplying, as the liquid, a physiological saline solution between the first electrode portion and the second electrode portion.
With this configuration, as a result of facilitating the flow of the direct current between the first electrode portion and the second electrode portion via the physiological saline solution, it is possible to efficiently remove a burnt deposit of the biological tissue attached to the first electrode portion.
In the above-described aspect, the high-frequency treatment tool may include a switching mechanism that switches between energizing of the first electrode portion by means of the high-frequency current and energizing thereof by means of the direct current.
With this configuration, it is possible to switch, by means of the switching mechanism, the type of the current used to energize the first electrode portion between when making an incision in the biological tissue and when removing a burnt deposit of the biological tissue attached to the first electrode portion in a simple manner.
In the above-described aspect, the power supply portion may apply the high-frequency current and the direct current to the first electrode portion in an overlapping manner.
A second aspect of the present invention is a medical system including: any one of the high-frequency treatment tools described above; and an endoscope having a channel into which the high-frequency treatment tool can be inserted.
A third aspect of the present invention is a high-frequency treatment tool operating method in which: a first electrode portion is used as a negative electrode; a second electrode portion that is electrically connected with the first electrode portion is used as a positive electrode; and a direct current is supplied between the first electrode portion and the second electrode portion.
In the above-described aspect, after the direct current is supplied between the first electrode portion and the second electrode portion in a state in which the first electrode portion is disposed so as to protrude from a distal end of a sheath, the first electrode portion and the sheath may relatively be moved in a direction in which the first electrode portion is pulled into the sheath, and attached matter attached on the first electrode portion may be pressed against a cutting edge of a cutter disposed in a distal-end portion of the sheath.
In the above-described aspect, a physiological saline solution may be supplied between the first electrode portion and the second electrode portion.
REFERENCE SIGNS LIST- 1 high-frequency treatment tool
- 3 sheath
- 3ainner hole
- 3ccoil
- 3dtube
- 3esheath distal-end member
- 7 opposing electrode (second electrode portion)
- 11 liquid feeding means
- 13 electrode portion (first electrode portion)
- 19 constant-current DC power source (power supply portion)
- 21 switching mechanism
- 23 DC electrode (second electrode portion)
- 27 cutter
- 27acutting edge
- 100 medical system
- X patient (subject)
- W physiological saline solution (liquid)